What EPA's radon map says about Erie County

Erie County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. That puts Erie County in the 100th percentile nationally for radon potential — higher than 100% of the counties EPA has rated.

Where Erie County sits nationally

About 950,602 people live in Erie County, New York, spread over 1,042.763 square miles. Averaged across its land area, Erie County runs about 912 people per square mile. Among counties sharing Erie County's EPA zone, it outranks 99% of them by population. EPA's geology-based Region 2 groups Erie County with 82 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Erie County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Erie County will test well under the action level, and EPA's guidance is to test regardless of zone.

If Erie County tests above the action level

Mitigation cost doesn't depend on Erie County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find New York's state radon program

Erie County's test kit answers today; a Airthings radon monitor keeps answering for Erie County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Erie County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.